Lubricating compositions



United States Patent 3,526,595 LUBRICATING COMPOSITIONS Serge E. Pellaton, East Orange, N..I., assignor, by mesne assignments, to Fairchild Chemical Corporation, a corporation of Delaware,

No Drawing. Continuation-impart of application Ser. No. 610,776, Jan. 23, 1967. This application May 29, 1967, Ser. No. 642,136

Int. Cl. Cm 1/40 US. Cl. 252-333 9 Claims ABSTRACT OF THE DISCLOSURE This invention is an improved boundary lubricant for water-base lubricating and cooling fluids having superior cooling efficiency as well as improved anti-weld, antiwear and extreme pressure lubricity. The boundary lubricants provided by this invention are broadly comprised of sulfonated oils, an alkanolamine, and a small percent by weight of a substituted cellulose, said cellulose substituted with a member selected from the group consisting of where R represents an alkyl group of from 1 to 2 carbon atoms and X represents an alkali metal.

This application is a continuation-in-part of my prior application Ser. No. 610,776, filed J an. 23, 1967 and now abandoned.

BACKGROUND OF INVENTION Field of the invention This invention relates to fluid lubricating compositions and more particularly to water-base lubricating and cooling fluids which are suitable for use in metal-forming, grinding, and machining operations. This invention is based on the discovery that a superior water-base lubricating and cooling fluid may be obtained through the use of a unique boundary lubricant formed from a mixture of sulfonated petroleum oils, an alkanolamine, and an alkali salt of a carboxyalkyl or hydroxyalkyl substituted cellulose. The water-base lubricating and cooling fluids provided by this invention have greatly improved cooling efliciency as Well as excellent anti-weld, anti-wear, and extreme pressure lubricity properties which render them superior to presently available commercial cooling fluids.

Description of the prior art Lubricating and cooling compositions have two fundamental properties: (1) rapid dissipation of the high frictional heat generated by the machining tool in contact with the work-piece, and (2) extreme pressure, anti-weld, and anti-wear lubricating properties. Heat dissipation is provided by a solvent, usually water, which constitutes the major constituent of the lubricating and cooling composition. Lubrication is provided by a soluble boundary lubricant which constitutes a minor portion of the composition, usually no more than 2 percent by weight. Commercially available lubricating and cooling compositions are usually composed of a mixture of (1) a water-soluble boundary lubricant, such as non-ionic and anionic surfactants or mixtures of both, (2) a corrosion inhibitor, such as borax, sodium nitrate, alkanolamines such as diethanol amine and triethanol amine, and condensation products of diethanol amine with fatty acids, and (3) an anti-foam agent, such as a dimethyl polysiloxane or similar silicon anti-foam or fatty acid esters 3,526,595 Patented Sept. 1, 1970 of higher alcohols (e.g. methyl stearate, tricresyl phosphate, C C alcohols).

Suitable anionic surfactants include phenolates, carboxylates and sul-fonates. Particularly satisfactory results have also been obtained by using water-soluble soaps such as sodium oleate as a boundary lubricant. Various other types of boundary lubricants have also been used in lubricating and cooling mixtures in conjunction with surfactants, in particular water-soluble sulfurized fatty acids or their derivatives, as well as chlorinated hydrocarbons and fats.

In addition to the three essential components of a cooling and lubricating composition, namely, the boundary lubricant, corrosion inhibitor and anti-foam agent, the cooling and lubricating mixture may also contain a germicide such as sodium O-phenol-phenoxide or methyl p-hydroxy benzoate, to stabilize it and the fluid in which it is employed, against fungal or bacterial growth.

SUMMARY OF THE INVENTION The water-base lubricating and cooling compositions provided by this invention have a cooling efliciency, as well as anti-wear anti-weld and high pressure lubricity properties that are substantially improved over commercially available cooling compositions. The lubricating and cooling compositions provided by this invention will provide as great as 350 percent more cooling effect than many commercially available cooling oils. Tool wear may be greatly reduced by the use of the lubricating compositions provided by this invention; in some applications tool life may be extended for as much as 500 percent over that of machine tools lubricated and cooled by commercially available compositions. The antiweld and high pressure lubricity properties of the lubricating and cooling compositions of this invention provide for improved quality in the finished work-piece of a metal working operation due to decrease frictional vibration and tool binding. The high pressure lubricity of the compositions provided herein has been measured by a Falex test machine to be greater than 4,000 pounds as compared with approximately 2,500 pounds for a widely used commercially available cooling composition.

Briefly stated, this invention is in a water-base fluid lubricating and cooling composition composed of a major amount of water and minor amounts of a boundary lubricant, a rust inhibitor and an anti-foam agent, in which said boundary lubricant consists of sulfonated oils, an alkanolamine, and a substituted cellulose, said cellulose substituted with a member selected from the group consisting of wherein R represents an alkyl group of from 1 to 2 carbon atoms and X represents analkali metal. Preferable substituted celluloses for this invention include sodi nmcarboxymethyl cellulose and sodium hydroxyethyl cellulose. In the preferred forms of this invention, the anti-foam agent is comprised of a major amount of water, about 8 percent by Weight of triethanol amine and about 8 percent by weight of chromium oleate. Preferably, a small quantity of glycerine may be added to the lubricating and cooling compositions disclosed herein to facilitate the mixing of the various components.

The following examples will illustrate two preferred forms of this invention and will demonstrate the superior properties of the lubricating and cooling compositions of this invention for a large variety of machining operations.

Example 1.-A water-base lubricating composition, designated Composition A, was prepared in the following manner. A solution, designated solution No. 1, was

formed by mixing 105 kilograms of water, 7 kilograms of glycerine and 350 grams of sodium carboxymethyl cellulose-CMC 1050. A second solution, designated solution No. 2, was formed by mixing 35 kilograms of water, 31.5 kilograms of triethanol amine and 31.5 kilograms of a mixture of sulfonated petroleum oilsPetromix No. 9a mixture of petroleum sulfonates, oleates, potassium abietate, sulfonated oils, and coupling agents (the alcohols of higher paraffins). A third solution, designated solution No. 3, was prepared by the use of 31.5 kilograms of a rust preventative (X-O027), 6.0 grams of a fungicide (Vancide BN), and 12 kilograms of an anti-foam agent. The X-0027 rust preventative is comprised of 55 percent water and minor amounts of phenylmercuries, morpholines, nitrogen compounds, coupling agents and an anti-foam agent. The Vancide BN fungicide contains as active agents orthosilicate esters and hydroxyquinoline. The anti-foam agent had been previously prepared by mixing into kilograms of water 1 kilogram of triethanol amine and 1 kilogram of chromium oleate.

Solution No. 2 was carefully mixed into solution No. 1, the solution being continuously agitated by a propeller mixer. Solution No. 3 was then added to the mixture of solutions 1 and 2 as mixing was continued. 0.3 gram of Jaune Ariable coloring agent was added for marketing purposes.

Composition A, prepared in the manner described above, was compared with a commercially available cooling composition, Ultralin. The Ultralin cooling composition is comprised of 83 percent water and minor amounts of polyethylene glycol, a mixture of ethers, a rust preventative, an anti-foam agent and a bactericide. Both Composition A and the Ultralin composition were diluted with water in a ratio of to 1 and were used to lubricate a tungsten carbide cutting tool which was used to finish a 2-inch diameter 20-40 steel rod rotating on a metal lathe at s.f.p.m. 165 The temperature of the cutting tool near the cutting edge was measured by a thermocouple. The temperature of the cutting tool with the Ultralin cooling composition was measured to be 265 C. In contrast, the temperature of the cutting tool with Composition A was measured to be 75 C.

Two finished rods, the first finished with the use of Ultralin and the second finished with Composition A, were microscopically studied. The scorings on the finish of the second rod were found to be approximately three times closer than that on the finish of the first rod. This difference indicates that the vibration of the cutting tool used with Composition A was considerably less than with Ultralin, due to the improved high speed lubricity of Composition A. The same two finished rods were measured for roughness by the use of an ASA standard surface analysis machine. The average distance between the peaks and valleys of the rod finished with the Ultralin composition was found to be .006 inch, whereas that of the rod finished with Composition A was found to be .002 inch.

Example 2 .-A second water-base lubricating composition designated Composition B was produced in the following manner. A solution, designated solution No. 1, was formed by mixing into 210 kilograms of water 3.50 kilograms of glycerine, and 0.75 kilograms of sodium hydroxyethyl celluloseCello-size. A second solution, designated solution No. 2, was produced by mixing into 70 kilograms of water, 3.15 kilograms of Petromix 9 and 31.5 kilograms of triethanol amine. Solution No. 3 was produced by mixing together, as in Example 1 above, 31.5 kilograms of rust preventative X-0027, 6.0 kilograms of fungicide (Vancide BN) and 12 kilograms of an antifoam agent. As in Example 1, the anti-foam agent had been previously prepared by mixing together 10 kilograms of water with one kilogram of triethanol amine and one kilogram of chromium oleate.

Both Composition B and Cimcool, a high speed cooling composition, were diluted with water in a ratio of 20 to 1 and compared as cooling compositions for a Bachler Screw Machine for machining Inconel X750, a hard-cobalt-nickel alloy. The Cimcool cooling com position is comprised of about 50 percent water, and minor amounts of polyethylene glycol, propylene oxide, nitrogen compounds, a rust preventative and an antifoam agent. It was found that through the use of Composition B the machining speed could be increased 75 percent, while still providing an excellent finish to the work, and tool wear was decreased more than 500 percent (with Cimcool it was necessary to replace tools once an hour, whereas with Composition B tools required sharpening or replacement once every five hours or more).

For an additional comparison Composition B and Cimcool were utilized to machine cast aluminium in a 6 turret metal lathe. It was found that through the use of Composition B machining speed could be increased 30 percent due to the lower friction provided by Composition B. It was also discovered that a new tap was required every seventy-two hours with Composition B, in contrast to once every three hours with Cimcool composition.

Cimcool and Composition B were tested for evaporation rates, and the evaporation rate of Composition B was approximately 2 percent by weight over a twentyfour-hour period, as opposed to 6 to 8 percent by weight loss over a twenty-four-hour period for Cimcool.

Example 3.-Composition A, Composition B, the Ultralin and Cimcool cooling compositions and a commercially available cutting oil were tested in a Falex test machine in dilutions of one part of lubricating composition to twenty parts water. In the Falex test machine the shaft was rotated at a speed of 295 r.p.m., and pressure was applied at the rate of 500 lbs/minute. The results of these tests are summarized below in Table I:

TABLE I Falex test Lubricating composition: pressure, lbs. Composition A 4000 Composition B 4000 Cimcool 2600 Ultralin 2950 The above test clearly demonstrates the lubricity and anti-bind properties of the cooling composition provided by this invention.

Example 4.The corrosion resistance of Ultralin, a commercially available lubricating and cooling composition, and Composition B were compared at dilutions of one part lubricating agent to one hundredparts of water by means of a Herbert Corrosion Test. Chips of cast iron were placed on the polished and degreased surface of two cast iron Herbert Corrosion Test blocks. The first test block was coated with the dilute solution of Composition B, and the second was coated with the dilute solution of Ultralin. The two test blocks were allowed to stand at room temperature for twenty-four hours, during which time the cooling composition completely evaporated. The cast iron chips on the two blocks were then microscopically examined for rust. The chips coated with the dilute Ultralin solution were found to show evidence of rust, whereas there was no evidence of rust on the chips coated with Composition B. This example demonstrates that the lubricating and cooling compositions provided by this agent provide a thin rust preventative coating to a workpiece even at low concentrations.

Example 5 .A water-base lubricating composition was Straight cutting oil prepared by thoroughly dispersing 0.76 part by Weight of carboxymethyl cellulose marketed under the mark CMC 7 HF, and approximately 61 parts of water. A second solution was then formed by mixing approximately 21 parts of water with 3.22 parts of triethanolamine and 13.75 parts of a mixture of sulfonated petroleum oils Petromix 9. A third solution was then prepared by mixing approximately 0.8 percent of a bactericide-Preveniol GDCand approximately 0.45 percent of an anti-foaming agentColloid 581Busing an appropriate amount of water to obtain a good dispersion. The second solution containing the amine and the sulfonated oils was then carefully mixed into the carboxymethyl cellulose solution and continuously agitated by a propeller mixer.

The third solution was then added to the mixture of the first two solutions as the mixing continued. During the mixing a small amount of coloring agent was added for marketing purposes. The total composition contained 81.75 percent water, 13.75 percent sulfonated oils, 3.22 percent of triethanolamine, 0.76 percent carboxymethyl cellulose, 0.08 percent bactericide, 0.45 percent anti-foaming agent, and a small amount of coloring agent.

This composition was then used in both rough face milling finish and pocket milling applications on titanium metal. -Upon examination of the wear lands on the cutting tool edges, this composition was found to be equal or superior to CO and can be used to replace CO in all known applications. This is particularly advantageous from an economical standpoint since it eliminates CO container rentals, storage for the CO tanks, obtaining tank refills, and also the high production cost of CO This composition was also used in face milling operations and end milling operations on steel. The resultant use of the lubricant of this invention in face milling operations showed a noticeable improvement in the finish and the one-half-inch diameter end mill tool life was increased by 30 percent over any other known fluid lubricating and cooling compositions. Tests on aluminum were also excellent.

The lubricating compositions of this invention also have other advantages. For example, foam tests showed that compositions of this invention settled within 15 seconds, while all others of which the applicant has knowledge take in excess of 15 minutes to settle. Heat thaw, rust tests and separation tests were also found to be excellent. The product is also odor free, clean, and will not stain garments. It leaves no scummy residue on the machine or production parts. It has surfactant or detergent action and will flush and clean the machine pump. It is anti-bacterial and will dry leaving a rust resistant film.

The sulfonated oils used in the compositions of this invention have a number of functions including the reduction of friction, although it is possible to use other oils for this purpose. Quite superior results were obtained by using the sulfonated oils, particularly in combination with the alkanolamines and carboxymethyl cellulose.

The same is true with respect to the alkanolamines which serve a corrosion inhibitor function. Other corrosion inhibitors could be used, but the alkanolamines, particularly triethanolamine, are quite superior, particularly in combination with the sulfonated oils and the carboxymethyl cellulose.

The amounts of the various materials which can be used can be varied quite widely, as will be apparent to those skilled in the art. The optimum amounts of carboxymethyl cellulose, sulfonated oils, and alkanolamines can readily be determined by routine experimentation.

The majority of the lubricating or cooling fluids of this invention is composed of course of water. The amount of carboxymethyl cellulose is advantageously in the range of 0.1 to 1.5% by weight of the total composition, and preferably about 0.75 percent. As low as 0.1 percent could also be used if desired.

The amount of sulfonated oils used will of course depend upon the amount of friction reduction desired, which will in turn depend upon the particular metal being worked and the speed at which it is being worked. Generally, anywhere from about 3 to 15 percent by weight of the total composition would be acceptable, and it is preferred in most instances to operates at the upper percentage level of between 13 and 15 percent.

Similarly, the amount of alkanolamines used will depend upon the particular alkanolamine selected for use and the amount of corrosion resistance desired, which will again depend upon the particular metal being Worked. Generally, anywhere from about 3 to 15 percent by weight of the total composition would be acceptable, and it is advantageous in most instances to use an amount between about 3 to 5 percent.

The amounts of the other materials can also be varied and used in sufficient amount to prevent bacteria or fungus activity and to prevent foaming. The particular bactericide or fungicide or foaming agent used can be selected quite readily by those skilled in the art.

I claim:

1. A water-base fiuid lubricating and cooling composition comprising a major amount of water and a minor amount of a boundary lubricant consisting essentially of 3 to 15% of a sulfonated oil, 3 to 15% of alkanol amine and 0.1 to 1.5% of a cellulose substituted with a member consisting of r o XOR or XOi 3R wherein R is an alkyl group of 1 to 2 carbon atoms and X and an alkali metal, said percentages based on the total weight of the composition.

2. The composition of claim 1 wherein the alkanol amine is triethanolamine.

3. The composition of claim 1 wherein the cellulose is an alkali metal carboxy methyl cellulose.

4. The composition of claim 1 containing as an additional ingredient a small amount of glycerine effective to facilitate the mixing of the various ingredients.

5. The composition of claim 1 containing as an additional ingredient an anti-foam agent.

6. In the process of metal machining, the step of cooling the work with a composition comprising a major amount of water and a minor amount of a boundary lubricant consisting essentially of 3 to 15% of a sulfonated oil, 3 to 15 of an alkanolamine and 0.1 to 1.5 of a cellulose substituted with a member selected from the group consisting of wherein R is an alkyl group of 1 to 2 carbon atoms and X is an alkali metal, said percentages being based on the total weight of the composition.

7. The process of claim 6 wherein the alkanol amine is triethanolamine.

8. The process of claim 6 wherein the cellulose is an alkali metal carboxy methy cellulose.

9. The process of claim 6 wherein the composition contains as an additional ingredient an anti-foam agent.

References Cited UNITED STATES PATENTS 1,979,469 11/1934 Johnson 8-6 2,346,124 4/1944 Dew 252-49.5 2,438,461 3/1948 Showalter 252-332 2,668,146 2/1954 Cafcas et al 252-42.1 X 3,341,454 9/1967 Chor et a1. 25222 DANIEL E. WYMAN, Primary Examiner W. I. SHINE, Assistant Examiner U.S. Cl. X.R. 

